Maybe a bug, maybe a welcome addition

....
My SP suffered a strained back (1 week, 80%) after striking out the last man in the 8th. When I went back on the field in the ninth, I was not asked to replace him. He ended up finishing out the game.
I don't ever remember seeing a player, pitcher or otherwise, remain in a game after any kind of injury. Is this an addition, or a bug? I think it makes sense that a player could suffer a DTD injury and not leave the game, but I've never seen it in OOTP.